Epidemiology of blood-borne viral infections in Afghanistan

Although a few studies have been done on transmissible blood-borne viral infections in high-risk groups, little attention has been given to assessing the infection status of the general population in Afghanistan. To investigate the epidemiological status in the general population, we tested the serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus (HDV), human immunodeficiency virus 1 (HIV-1) and human T-cell leukemia virus (HTLV) infections. In total, 492 samples were selected randomly from Nangarhar, Herat, Mazar-e Sharif, Kandahar, and Kabul from subjects between 25 and 70 years old. The samples were tested for the presence of HBsAg, anti-HBs, anti-HBc, anti-HDV, anti-HCV, anti-HIV-1 and anti-HTLV I/II antibodies using chemiluminescent immunoassays on Abbott Architect automated platforms. In addition, 220 HBsAg-positive samples identified among 5897 samples from the general population of the same regions of Afghanistan were included in the study and tested for both HBsAg and anti-HDV to investigate HDV prevalence in the country. Viral loads of HBV, HCV and HDV were determined in all seropositive samples using Ampliprep/Cobas TaqMan HBV, HCV, Test Roche (CA, USA), and an in-house method, respectively. Out of 492 samples, 31 (6.3%), 136 (27.6%) and 149 (30.3%) were found to be positive for HBsAg, anti-HBs and anti-HBc, respectively. Anti-HDV positivity was detected in five (2.1%) out of 234 HBsAg-positive samples (including 14 of the randomly selected samples that were not among the 220 previously identified as HBsAg positive). Only eight out of 492 (1.6%) subjects were positive for anti-HCV antibodies. Seven out of 489 (1.4%) were positive for anti-HIV-1 antibodies, and three out of 466 cases (0.6%) were positive for anti-HTLV I/II antibodies. These results suggest that Afghanistan is an intermediate endemic region for HBV, HDV and HCV infection. The prevalence of HIV-1 seems to be significantly higher than the global prevalence and that of the eastern Mediterranean region. In addition, the HTLV I/II screening results suggest that these viruses should be monitored in Afghanistan to confirm the trend observed in the current study.